Various machines have been designed and are in commercial usage for exercising various parts of the body. Examples of such machines are shown in U.S. Pat. Nos. 3,640,527 to Proctor; 3,912,261 to Lambert; 4,296,926 to Anzaldua et al; and 4,494,751 to Schnell.
Despite the fact that there are so many exercise machines on the market, there still is a need for an exercise machine that will adequately exercise the posterior shoulder.